Method of producing piston rings



Nov. 10 1925.

. 1,561,336 J. F. MCGLENN METHOD OF PRODUCING PISTON RINGS FiIQdNOVQ 25. 1924 Patented Nov. 10, 1925,

omrrso sir Ares JOHN F. MCGLENN, or HARVEY, some DAKOTA.

Maureen or PRODUCING rrs'roiv nines.

Application filed November 25, 1924-. Serial No. 752,180.

To'all whom it may 004mm:

Be it known that 1, JOHN F. ll'iGGLENN, a citizen of the United States, residing at Harvey, in the county of ells and State of North Dakota, have invented certain new and useful Improvements in Methods of Producing Piston Rings, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to improvements in the method of constructing piston rings.

An important object of the invention is the construction of piston ring, which when the ends are drawn together as in placement in the cylinder in which it is to be used, will assume a perfect circular shape, and not be distorted as in the usual construction of such rings.

A further and more specific object of the invention is the step in the method of constructing piston rings of securing together the ends of the ring after the usual lap joint has been formed therein, and the reduction of the ring with the ends so secured to the proper internal and external diameter.

These and other objects are accomplished by the method hereinafter set forth and illustrated in the accompanying drawings, wherein for the purpose of illustration, 1 have shown the various steps of the method producing a ring in accordance with my invention and in which Figure 1 is a side elevation of a casting from which the rough rings are cut;

Figure 2 is a perspective of one of the rings severed from the casting;

Figure 3 is a perspective view of the ring of Fig. 2 after the cut for providing the lap joint is made therein;

Figure 4 is a view of the lap jointed ring with its ends drawn together for joining;

Figure 5 is a view showing the ring ap plied to the face plate with the ends secured together for exterior finishing;

Figure 6 is a fragmentary view showing the device applied for the interior finishing and the finishing completed, the pin 16 having been removed by the out; and

Figure 7 is a perspective view showingthe pin 16 and the bore 15 for its reception as formed in the lap joint.

The first step in the production of a ring is the casting of a cylinder 10 of slightly greater external and smaller internal diameter than the ring finally to be produced. This is finished externally by turning in a lathe to a diameter slightly greater than the ring to be produced. The casting is then separated into rings 11 in the'usual manner, being either in theprocess of separation or after separation reduced to their proper final width; In the formation oftlie casting care is taken that the thickness ofthe casting is such that the internal diameter is smaller than the external diameter of such rings at this-step in construction thereof in the usual process of manufacture, for a purpose presently to appear.

The ring 11 is then severed in the: usual manner as at 12 to produce a lap joint of the type usually employed in pistonrings, this lap oint beii'ig of any type which may be preferred. The ends of the ring are then drawn together so that thelap joint, generally designated at 13;, is closedand in the position which it will assume when the ring is finally placed in the cylinder for use. This drawing together may be performed by a suitable clamp 14. While in this position a small opening is drilled through the overlapping sections of the lap joint, adjacent the inner margin of the ring, as indicated at 15, and a pin 16 inserted in these openings, after which the clamp 14 is removed.

It will be obvious at this time the ring 11 will be distorted and not in the shape of a true circle. It will also be obvious that this is true in the ordinary construction of a ring in which after finishing the exterior of the casting 10 the amount removed by the cut 12 is such that the ring theoretically assumes the proper diameter when the ends of the lap joint are drawn together. This distortion will prevent proper fitting of the ring in the cylinder and in order to remove this, I apply the ring to a face plate 17 and clamp it to the face plate from the inside of the ring as indicated at 18. The exterior diameter of the ring is then reduced to the exterior diameter desired in the finished ring after which the clamps 18 are reversed, as shown in Figure 6. In this reversal, care is taken that one of the clamps-18 overlies the lap joint 13. The internal diameter of the ring is then produced and in making the necessary cut the pin 16 and the bore 15 formed for its reception are removed, the bore having been formed immediately adjacent the inner margin of the ring.

It will be obvious that a ring constructed in accordance with the above method will be in the form of a true circle when the ends of a lap joint are brought together, and will. accordingly have atrue fit in the cylinder preventing scoring of the piston ring and cylinder, which is at present a common occurrence even when sufiicient lubrication is maintained for rings of the proper fit. It will also be obvious that the perfect fit between the ring and cylinder will eliminate, to a great extent, the leakage ordinarily present, this greatly increasing the efficiency of the engine. Such a ring will be perfectly circular when its ends are drawn together and will in addition be of uniform thickness throughout its length so that there will be a reduction in the loss occurring in the placement of the piston ring which at present is materially increased by reason of the fact that the ends of the ring adjacent the split are of considerably less thickness than the portions of the ring diametrically opposed thereto.

1. The method of producing piston rings consisting in providing a solid ring of greater exterior diameter and less interor diame ter than the ring finally to be produced, spltting the ring and removing material in forming the split of such quantity that when the ends of the split are drawn together the external diameter of the ring is still greater than the external diameter of the ring to be produced, securing such ends together by a securing element lying wholly within the surfaces of the ring thus produced and finishing the exterior surface of the ring to the diameter of the ring to be produced with the ends so secured and removing the seeuring means by the finishing of the interior surface of the ring.

2. The method of producing piston rings consisting in providing a split lap joint ring of greater external diameter and less internal diameter than the ring finally to be produced. when the ends of the lap joint are drawn together, securing ends of the lap joint together by a pin extending tl'irough the lap joint adjacentthe interior margin of the ring finishing the exterior surface of the ring to the proper size with the ends so secured and then finishing the interior surface of the ring and removing the pin by said finishing.

In testimony whereof I hereunto aiiix my signature.

JOHN F. MoGLENNr 

